QuinolonesFolic Acid Antagonists

Urinary TractAntiseptics

Fluoroquinolones

Bactericid

Ciprofloxacin

•Useful in treating infections caused by many Enterobacteriaceae & other gram-negative bacilli (E. coli).

•The drug of choice for prophylaxis and treatment of anthrax

•The most potent of the fluoroquinolones for Pseudomonas aeruginosa infections

•Alternative to more toxic drugs, such as the aminoglycosides

•Act synergistically with β-Iactams, and is also of benefit in treating resistant tuberculosis

•Levels are high in bone, urine, kidney & prostatic tissue (but not prostatic fluid)

•Concentrations in the lung exceed those in serum

•Penetration into cerebrospinal fluid is low except for ofloxacin, for which concentrations can be as high as ninety percent of those in the serum

•The fluoroquinolones also accumulate in macrophages and polymorphonuclear leukocytes, thus being effectiveagainst intracellular organisms such as Legionella pneumophila.

Adverse reactions

Gastrointestinal: nausea, vomiting, and diarrhea

Central nervous system problems: headache & dizziness or lightheadedness (Cautiously in epilepsy)

Phototoxicity

Liver toxicity: Trovafloxacin

Connective tissue problems: should be avoided in pregnancy, nursing mothers & children under eighteen years

Contraindications: Sparfloxacin & Moxifloxacin prolong the QT interval and, thus, should not be used in patients who are predisposed to arrhythmias or are taking antiarrhythmic medications

•Drug interactions:

•Ciprofloxacin & Ofloxacin: increase the serum levels of theophylline by inhibiting its metabolism

• Third- and fourth-generation: raise the serum levels of warfarin, caffeine & cyclosporine

•Cimetidine interferes with elimination of the fluoroquinolones

SULFONAMIDES

Bacteriostatic

•Sulfasalazine is not absorbed orally or as suppository:

•For treatment of chronic inflammatory bowel disease (for example,Crahn disease or ulcerative colitis)

•Local intestinal flora split sulfasalazine into sulfapyridine and 5-aminosalicylate, with the latter exerting the anti-inflammatory effect

Adverse effect

•Crystalluria

•Hypersensitivity

•Hemopoietic disturbances: with glucose 6-phosphate dehydrogenase deficiency

•Kernicterus

•Contraindications:

•should be avoided in newborns and infants less than two months of age,

as well as for pregnant women at term

•should not be given to patients receiving methenamine for UTls

TRIMETHOPRIM

•may be used alone in the treatment of acute UTls

•treatment of bacterial prostatitis (although fluoroquinolones are preferred) and vaginitis

• کلیوی دفع

•administration of folinic acid

CO-TRIMOXAZOLE:

(trimethoprim + sulfamethoxazol)

Adverse effects:

•Hematologic:

Megaloblastic anemia (folinic acid)

Hemolytic anemia (glucose 6-phosphate dehydrogenase defi-iency due to the sulfamethoxazole)

Drug Interactions:

•Prolonged prothrombin times in patients receiving both trimethoprim and warfarin

•The plasma half-life of phenytoin may be increased

•Methotrexate levels may rise due to displacement from albumin binding sites by sulfamethoxazole

URINARY TRACT ANTISEPTICS

A. Methenamin

Orally

Contraindicated in patients with hepatic insufficiency

Eliminated in the urine

Adverse effects:

The major side effect : gastrointestinal distress

at higher doses: albuminuria, hematuria, and rashes

Methenamine mandelate is contraindicated in patients with renal insufficiency, because mandelic acid may precipitate

Sulfonamides react with formaldehyde, and must not be used concomitantly with methenamine

B. Nitrofurantoin

Less common because of its narrow antimicrobial spectrum and toxicity

Sensitive bacteria reduce the drug to an active agent that inhibits various enzymes and damages DNA

Antibiotic activity is greater in acidic urine

Bacteriostatic

Useful against E. coli, but other common urinary tract gram-negative bacteria maybe resistant

Gram-positive cocci are susceptible

Adverse effects:

Gastrointestinal disturbances, acute pneumonitis, and neurologic problems